linux.git/include, branch dev

profiling: attempt to remove per-cpu profile flip buffer

2024-07-29T17:58:28+00:00

This is the really old legacy kernel profiling code, which has long since been obviated by "real profiling" (ie 'prof' and company), and mainly remains as a source of syzbot reports. There are anecdotal reports that people still use it for boot-time profiling, but it's unlikely that such use would care about the old NUMA optimizations in this code from 2004 (commit ad02973d42: "profile: 512x Altix timer interrupt livelock fix" in the BK import archive at [1]) So in order to head off future syzbot reports, let's try to simplify this code and get rid of the per-cpu profile buffers that are quite a large portion of the complexity footprint of this thing (including CPU hotplug callbacks etc). It's unlikely anybody will actually notice, or possibly, as Thomas put it: "Only people who indulge in nostalgia will notice :)". That said, if it turns out that this code is actually actively used by somebody, we can always revert this removal. Thus the "attempt" in the summary line. [ Note: in a small nod to "the profiling code can cause NUMA problems", this also removes the "increment the last entry in the profiling array on any unknown hits" logic. That would account any program counter in a module to that single counter location, and might exacerbate any NUMA cacheline bouncing issues ] Link: https://lore.kernel.org/all/CAHk-=wgs52BxT4Zjmjz8aNvHWKxf5_ThBY4bYL1Y6CTaNL2dTw@mail.gmail.com/ Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git [1] Cc: Thomas Gleixner Cc: Tetsuo Handa Signed-off-by: Linus Torvalds

minmax: simplify min()/max()/clamp() implementation

2024-07-29T03:24:12+00:00

Now that we no longer have any C constant expression contexts (ie array size declarations or static initializers) that use min() or max(), we can simpify the implementation by not having to worry about the result staying as a C constant expression. So now we can unconditionally just use temporary variables of the right type, and get rid of the excessive expansion that used to come from the use of __builtin_choose_expr(__is_constexpr(...), .. to pick the specialized code for constant expressions. Another expansion simplification is to pass the temporary variables (in addition to the original expression) to our __types_ok() macro. That may superficially look like it complicates the macro, but when we only want the type of the expression, expanding the temporary variable names is much simpler and smaller than expanding the potentially complicated original expression. As a result, on my machine, doing a $ time make drivers/staging/media/atomisp/pci/isp/kernels/ynr/ynr_1.0/ia_css_ynr.host.i goes from real 0m16.621s user 0m15.360s sys 0m1.221s to real 0m2.532s user 0m2.091s sys 0m0.452s because the token expansion goes down dramatically. In particular, the longest line expansion (which was line 71 of that 'ia_css_ynr.host.c' file) shrinks from 23,338kB (yes, 23MB for one single line) to "just" 1,444kB (now "only" 1.4MB). And yes, that line is still the line from hell, because it's doing multiple levels of "min()/max()" expansion thanks to some of them being hidden inside the uDIGIT_FITTING() macro. Lorenzo has a nice cleanup patch that makes that driver use inline functions instead of macros for sDIGIT_FITTING() and uDIGIT_FITTING(), which will fix that line once and for all, but the 16-fold reduction in this case does show why we need to simplify these helpers. Cc: David Laight Cc: Lorenzo Stoakes Signed-off-by: Linus Torvalds

minmax: make generic MIN() and MAX() macros available everywhere

2024-07-28T22:49:18+00:00

This just standardizes the use of MIN() and MAX() macros, with the very traditional semantics. The goal is to use these for C constant expressions and for top-level / static initializers, and so be able to simplify the min()/max() macros. These macro names were used by various kernel code - they are very traditional, after all - and all such users have been fixed up, with a few different approaches: - trivial duplicated macro definitions have been removed Note that 'trivial' here means that it's obviously kernel code that already included all the major kernel headers, and thus gets the new generic MIN/MAX macros automatically. - non-trivial duplicated macro definitions are guarded with #ifndef This is the "yes, they define their own versions, but no, the include situation is not entirely obvious, and maybe they don't get the generic version automatically" case. - strange use case #1 A couple of drivers decided that the way they want to describe their versioning is with #define MAJ 1 #define MIN 2 #define DRV_VERSION __stringify(MAJ) "." __stringify(MIN) which adds zero value and I just did my Alexander the Great impersonation, and rewrote that pointless Gordian knot as #define DRV_VERSION "1.2" instead. - strange use case #2 A couple of drivers thought that it's a good idea to have a random 'MIN' or 'MAX' define for a value or index into a table, rather than the traditional macro that takes arguments. These values were re-written as C enum's instead. The new function-line macros only expand when followed by an open parenthesis, and thus don't clash with enum use. Happily, there weren't really all that many of these cases, and a lot of users already had the pattern of using '#ifndef' guarding (or in one case just using '#undef MIN') before defining their own private version that does the same thing. I left such cases alone. Cc: David Laight Cc: Lorenzo Stoakes Signed-off-by: Linus Torvalds

minmax: simplify and clarify min_t()/max_t() implementation

2024-07-28T20:50:01+00:00

This simplifies the min_t() and max_t() macros by no longer making them work in the context of a C constant expression. That means that you can no longer use them for static initializers or for array sizes in type definitions, but there were only a couple of such uses, and all of them were converted (famous last words) to use MIN_T/MAX_T instead. Cc: David Laight Cc: Lorenzo Stoakes Signed-off-by: Linus Torvalds

Merge tag 'cxl-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2024-07-28T16:33:28+00:00

Pull CXL updates from Dave Jiang: "Core: - A CXL maturity map has been added to the documentation to detail the current state of CXL enabling. It provides the status of the current state of various CXL features to inform current and future contributors of where things are and which areas need contribution. - A notifier handler has been added in order for a newly created CXL memory region to trigger the abstract distance metrics calculation. This should bring parity for CXL memory to the same level vs hotplugged DRAM for NUMA abstract distance calculation. The abstract distance reflects relative performance used for memory tiering handling. - An addition for XOR math has been added to address the CXL DPA to SPA translation. CXL address translation did not support address interleave math with XOR prior to this change. Fixes: - Fix to address race condition in the CXL memory hotplug notifier - Add missing MODULE_DESCRIPTION() for CXL modules - Fix incorrect vendor debug UUID define Misc: - A warning has been added to inform users of an unsupported configuration when mixing CXL VH and RCH/RCD hierarchies - The ENXIO error code has been replaced with EBUSY for inject poison limit reached via debugfs and cxl-test support - Moving the PCI config read in cxl_dvsec_rr_decode() to avoid unnecessary PCI config reads - A refactor to a common struct for DRAM and general media CXL events" * tag 'cxl-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/core/pci: Move reading of control register to immediately before usage cxl: Remove defunct code calculating host bridge target positions cxl/region: Verify target positions using the ordered target list cxl: Restore XOR'd position bits during address translation cxl/core: Fold cxl_trace_hpa() into cxl_dpa_to_hpa() cxl/test: Replace ENXIO with EBUSY for inject poison limit reached cxl/memdev: Replace ENXIO with EBUSY for inject poison limit reached cxl/acpi: Warn on mixed CXL VH and RCH/RCD Hierarchy cxl/core: Fix incorrect vendor debug UUID define Documentation: CXL Maturity Map cxl/region: Simplify cxl_region_nid() cxl/region: Support to calculate memory tier abstract distance cxl/region: Fix a race condition in memory hotplug notifier cxl: add missing MODULE_DESCRIPTION() macros cxl/events: Use a common struct for DRAM and General Media events

Merge tag 'block-6.11-20240726' of git://git.kernel.dk/linux

2024-07-27T22:28:53+00:00

Pull block fixes from Jens Axboe: - NVMe pull request via Keith: - Fix request without payloads cleanup (Leon) - Use new protection information format (Francis) - Improved debug message for lost pci link (Bart) - Another apst quirk (Wang) - Use appropriate sysfs api for printing chars (Markus) - ublk async device deletion fix (Ming) - drbd kerneldoc fixups (Simon) - Fix deadlock between sd removal and release (Yang) * tag 'block-6.11-20240726' of git://git.kernel.dk/linux: nvme-pci: add missing condition check for existence of mapped data ublk: fix UBLK_CMD_DEL_DEV_ASYNC handling block: fix deadlock between sd_remove & sd_release drbd: Add peer_device to Kernel doc nvme-core: choose PIF from QPIF if QPIFS supports and PIF is QTYPE nvme-pci: Fix the instructions for disabling power management nvme: remove redundant bdev local variable nvme-fabrics: Use seq_putc() in __nvmf_concat_opt_tokens() nvme/pci: Add APST quirk for Lenovo N60z laptop

Merge tag 'io_uring-6.11-20240726' of git://git.kernel.dk/linux

2024-07-27T22:22:33+00:00

Pull io_uring fixes from Jens Axboe: - Fix a syzbot issue for the msg ring cache added in this release. No ill effects from this one, but it did make KMSAN unhappy (me) - Sanitize the NAPI timeout handling, by unifying the value handling into all ktime_t rather than converting back and forth (Pavel) - Fail NAPI registration for IOPOLL rings, it's not supported (Pavel) - Fix a theoretical issue with ring polling and cancelations (Pavel) - Various little cleanups and fixes (Pavel) * tag 'io_uring-6.11-20240726' of git://git.kernel.dk/linux: io_uring/napi: pass ktime to io_napi_adjust_timeout io_uring/napi: use ktime in busy polling io_uring/msg_ring: fix uninitialized use of target_req->flags io_uring: align iowq and task request error handling io_uring: kill REQ_F_CANCEL_SEQ io_uring: simplify io_uring_cmd return io_uring: fix io_match_task must_hold io_uring: don't allow netpolling with SETUP_IOPOLL io_uring: tighten task exit cancellations

Merge tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux

2024-07-27T20:44:54+00:00

Pull Rust updates from Miguel Ojeda: "The highlight is the establishment of a minimum version for the Rust toolchain, including 'rustc' (and bundled tools) and 'bindgen'. The initial minimum will be the pinned version we currently have, i.e. we are just widening the allowed versions. That covers three stable Rust releases: 1.78.0, 1.79.0, 1.80.0 (getting released tomorrow), plus beta, plus nightly. This should already be enough for kernel developers in distributions that provide recent Rust compiler versions routinely, such as Arch Linux, Debian Unstable (outside the freeze period), Fedora Linux, Gentoo Linux (especially the testing channel), Nix (unstable) and openSUSE Slowroll and Tumbleweed. In addition, the kernel is now being built-tested by Rust's pre-merge CI. That is, every change that is attempting to land into the Rust compiler is tested against the kernel, and it is merged only if it passes. Similarly, the bindgen tool has agreed to build the kernel in their CI too. Thus, with the pre-merge CI in place, both projects hope to avoid unintentional changes to Rust that break the kernel. This means that, in general, apart from intentional changes on their side (that we will need to workaround conditionally on our side), the upcoming Rust compiler versions should generally work. In addition, the Rust project has proposed getting the kernel into stable Rust (at least solving the main blockers) as one of its three flagship goals for 2024H2 [1]. I would like to thank Niko, Sid, Emilio et al. for their help promoting the collaboration between Rust and the kernel. Toolchain and infrastructure: - Support several Rust toolchain versions. - Support several bindgen versions. - Remove 'cargo' requirement and simplify 'rusttest', thanks to 'alloc' having been dropped last cycle. - Provide proper error reporting for the 'rust-analyzer' target. 'kernel' crate: - Add 'uaccess' module with a safe userspace pointers abstraction. - Add 'page' module with a 'struct page' abstraction. - Support more complex generics in workqueue's 'impl_has_work!' macro. 'macros' crate: - Add 'firmware' field support to the 'module!' macro. - Improve 'module!' macro documentation. Documentation: - Provide instructions on what packages should be installed to build the kernel in some popular Linux distributions. - Introduce the new kernel.org LLVM+Rust toolchains. - Explain '#[no_std]'. And a few other small bits" Link: https://rust-lang.github.io/rust-project-goals/2024h2/index.html#flagship-goals [1] * tag 'rust-6.11' of https://github.com/Rust-for-Linux/linux: (26 commits) docs: rust: quick-start: add section on Linux distributions rust: warn about `bindgen` versions 0.66.0 and 0.66.1 rust: start supporting several `bindgen` versions rust: work around `bindgen` 0.69.0 issue rust: avoid assuming a particular `bindgen` build rust: start supporting several compiler versions rust: simplify Clippy warning flags set rust: relax most deny-level lints to warnings rust: allow `dead_code` for never constructed bindings rust: init: simplify from `map_err` to `inspect_err` rust: macros: indent list item in `paste!`'s docs rust: add abstraction for `struct page` rust: uaccess: add typed accessors for userspace pointers uaccess: always export _copy_[from|to]_user with CONFIG_RUST rust: uaccess: add userspace pointers kbuild: rust-analyzer: improve comment documentation kbuild: rust-analyzer: better error handling docs: rust: no_std is used rust: alloc: add __GFP_HIGHMEM flag rust: alloc: fix typo in docs for GFP_NOWAIT ...

Merge tag 'devicetree-fixes-for-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2024-07-27T19:46:16+00:00

Pull more devicetree updates from Rob Herring: "Most of this is a treewide change to of_property_for_each_u32() which was small enough to do in one go before rc1 and avoids the need to create of_property_for_each_u32_some_new_name(). - Treewide conversion of of_property_for_each_u32() to drop internal arguments making struct property opaque - Add binding for Amlogic A4 SoC watchdog - Fix constraints for AD7192 'single-channel' property" * tag 'devicetree-fixes-for-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: dt-bindings: iio: adc: ad7192: Fix 'single-channel' constraints of: remove internal arguments from of_property_for_each_u32() dt-bindings: watchdog: add support for Amlogic A4 SoCs

Merge tag 'firewire-fixes-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

2024-07-27T19:35:12+00:00

Pull firewire fixes from Takashi Sakamoto: "The recent integration of compiler collections introduced the technology to check flexible array length at runtime by providing proper annotations. In v6.10 kernel, a patch was merged into firewire subsystem to utilize it, however the annotation was inadequate. There is also the related change for the flexible array in sound subsystem, but it causes a regression where the data in the payload of isochronous packet is incorrect for some devices. These bugs are now fixed" * tag 'firewire-fixes-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: ALSA: firewire-lib: fix wrong value as length of header for CIP_NO_HEADER case Revert "firewire: Annotate struct fw_iso_packet with __counted_by()"